In general, a numerical control (hereinafter referred to as NC) apparatus is comprised of an NC control unit, a commanding section mainly consisting of an NC operation panel and a driving section configured to have a servo amplifier, a main spindle amplifier, a motor or a detector. At present, a CNC (Computerized NC) apparatus incorporating a high-performance dedicated microcomputer and having ability to realize complicated and advanced control with high reliability is also used as a kind of the NC apparatus.
The NC apparatus is also capable of performing sequence control according to an input signal from a sensor, a switch, or the like set in a machine tool. A target of the control is an operation involved around a machine such as tool replacement or cutting chip removal. A description of a series of machining operations for the NC apparatus is called NC programming. This represents a tool path, a machining condition, or the like that is necessary for the machining in a form of commands for the NC apparatus. The NC program can be downloaded from an external program automatic generating apparatus to the NC apparatus or can be directly inputted from the NC operation panel.
In general, the NC apparatus is used in a field where higher-speed and more highly accurate control, which cannot be realized in a system constructed by combining a general-purpose sequencer and a general-purpose servo, is required. Such an NC apparatus has a high real-time property for performing a response at high speed of 0.5 millisecond or less in a servo system and can perform highly accurate control that enables control with a 0.1 micrometer level. The NC apparatus also has a stable characteristic by which the NC apparatus is allowed to perform advanced servo acceleration and deceleration control so as not to cause vibration while having the high real-time property and performing the highly-accurate control. The NC apparatus is capable of performing correction control for a machine in adapting to backlash, twist, bend, expansion and contraction, and the like that may occur because of rigid factors of a machine. The NC apparatus is also capable of performing synchronous control by which one workpiece moving to another machining area can be machined simultaneously with a plurality of gears without stopping rotation of the rotating workpiece.
The NC apparatus is also capable of implementing an interactive programming for interactively inputting a machining shape and creating a machining program, a graphic simulation function for simulation of the machining and for calculating a machining time, and the like.
In recent years, in a factory, to immediately respond to changes in a production situation and the like, it has become important to quickly perform reference to and evaluation of a change in information concerning production in production facilities. Therefore, a machine tool is also requested to accurately and quickly perform reference to and evaluation of machining information immediately responding to a change in a machining situation. For that reason, an NC apparatus having machining information communication functions explained below has been proposed and put to practical use. One is a function of reading, after designating a file name in the NC apparatus, machining information such as a machining program from an intermediate personal computer for communication, a host computer, or the like. The other is a function of transferring files of a machining plan and a work instruction from the host computer or the like to the NC apparatus online.
Further, in recent years, products and technologies of networks, personal computers and servers have been advanced. On the background of this advancement, there has been a growing demand for a system that can easily realize approaches to quality improvement of products and quick responses to changes in business environment by making use of a data processing apparatus (DB) that collects data matching a specific theme, stores and manages the data in various servers on a network, and enables facilitation of search and extraction, and reuse of desired data and use of DB applications.
For example, Patent Literature 1 discloses, as an NC apparatus having a machining information communication function, a system having structure in which an FA (Factory Automation) network having a programmable controller, a data file that stores data acquired from the programmable controller, and a user application are connected via a data managing apparatus. The data managing apparatus functions as a middleware between the programmable controller and a set of the data file and the user application, which performs processing for storing data collected from a plurality of PLCs in the data file and giving notice to the user application.